Look at it from the customers point of view - what's in this group for me?
Without any easily identifiable advantage it's difficult to see how customers (sailors owners lurkers whatever) would find the product attractive enough to commit.
What's in it for me?
Nothing, if you don't care that multihulls are becoming harder to insure - trimarans in particular - and you can't obtain any fact based evidence from the insurance industry that multis are a greater risk than any other type of boat. And if you can't insure, you can't race and the value of your investment is severely reduced.
Nothing, if you believe OMR is fine as it is and doesn't need any improvement or changes to accommodate foils, canting rigs etc - or just in need of a general review to satisfy yourself that it produces fair results across the entire fleet of different sizes and speeds of multis.
Nothing, if you don't subscribe to the view that strength in numbers can often produce negotiated outcomes superior to going alone.
Nothing, if you don't want to have an input into how things like national championships are organised and run. Perhaps better to let someone else carry the load and criticise from the sidelines?
Nothing if you are actually a monohull sailor.